Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS6337294 B1
Publication typeGrant
Application numberUS 09/443,740
Publication dateJan 8, 2002
Filing dateNov 19, 1999
Priority dateSep 24, 1996
Fee statusPaid
Also published asUS5958803, US6048581, WO1998013198A1
Publication number09443740, 443740, US 6337294 B1, US 6337294B1, US-B1-6337294, US6337294 B1, US6337294B1
InventorsJohn Cleveland Waldrop, III
Original AssigneeThe Boeing Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Elastic ground plane
US 6337294 B1
Abstract
An elastic ground plane (50) has an environmental coating (58) attached to a surface of a fabric (54) having a plurality of fibers. A conductive substance (56) is applied to the fabric (54) to coat the fabric (54).
Images(4)
Previous page
Next page
Claims(30)
What is claimed is:
1. An elastic ground plane comprising:
an environmental coating;
a fabric having a plurality of fibers capable of a minimum of 100% elongation, the fabric attached on a first surface thereof the environmental coating; and
a conductive substance coating the fabric.
2. The elastic ground plane of claim 1, further including an adhesive applied to a second side of the fabric.
3. The elastic ground plane of claim 2, wherein the adhesive is an elastomer.
4. The elastic ground plane of claim 2, further including a reinforced elastomer attached to the adhesive.
5. The elastic ground plane of claim 1, wherein the environmental coating is an elastomer.
6. The elastic ground plane of claim 1, wherein the environmental coating is an elastomeric coating selected from the group of fluorosilicones, fluoroelastomers, silicones, thermoplastic elastomers and urethanes.
7. The elastic ground plane of claim 1, wherein the plurality of fibers include an elastic fiber.
8. The elastic ground plane of claim 1, wherein the fabric has a warp knit style weave.
9. The elastic ground plane of claim 1, wherein the conductive substance is a metal.
10. The elastic ground plane of claim 9, wherein the conductive substance is between 5 and 40 weight percent of the fabric.
11. An elastic conductive material, comprising:
a plurality of fibers forming a plane wherein the plane is capable of 100% elongation;
a conductive substance coating the plurality of fibers; and
an elastomeric coating attached to a surface of the plane.
12. The elastic conductive material of claim 11, wherein a tensile moduli of the plane is less than 1000 pounds per square inch.
13. The elastic conductive material of claim 12, wherein a resistance is less than 0.8 Ohms per square throughout an operating range.
14. The elastic conductive material of claim 11, further including an elastomeric adhesive covering a side of the elastomeric coating.
15. An elastic ground plane adapted to be secured to a stretchable surface, the elastic ground plane comprising:
a fabric having a plurality of fibers, the fabric being adapted to be secured to said stretchable surface and capable of elongation;
a conductive substance coating the plurality of fibers;
an environmental coating applied to at least a portion of a first surface of the fabric; and
wherein the elastic ground plane is capable of a minimum of 100% elongation and is in accordance with that of the stretchable surface to which it is secured.
16. The elastic ground plane of claim 15, further including an adhesive applied to a second side of the fabric for securing the fabric to the stretchable surface.
17. The elastic ground plane of claim 16, wherein the adhesive is an elastomer.
18. The elastic ground plane of claim 15, wherein the environmental coating is an elastomeric coating selected from the group of fluorosilicones, fluoroelastomers, silicones, thermoplastic elastomers and urethanes.
19. The elastic ground plane of claim 15, wherein the plurality of fibers include an elastic fiber.
20. The elastic ground plane of claim 15, wherein the fabric has a warp knit style weave.
21. The elastic ground plane of claim 15, wherein the conductive substance is a metal.
22. The elastic ground plane of claim 21, wherein the conductive substance is between 5 and 40 weight percent of the fabric.
23. An elastic conductive material, comprising:
a plurality of fibers forming a plane, capable of 100% elongation;
a conductive substance coating the plurality of fibers; and
an elastomeric coating attached to a surface of the plane and capable of elongation.
24. The elastic conductive material of claim 23, wherein a tensile moduli of the plane is less than 1000 pounds per square inch.
25. The elastic conductive material of claim 24, wherein a resistance is less than 0.8 Ohms per square throughout an operating range.
26. The elastic conductive material of claim 23, further including an elastomeric adhesive covering an other side of the elastomeric coating.
27. An elastomeric structure incorporating electromagnetic shielding, the structure comprising:
an elastomeric substrate capable of a minimum of 100% elongation;
a fabric having a plurality of fibers forming a panel, the fabric being securable to the elastomeric substrate and further being capable of a same degree of elongation in accordance with that of the elastomeric substrate; and
a conductive substance coating the plurality of fibers such that the fibers provide an electromagnetic shielding effect to the elastomeric structure without impeding elongation of the fabric.
28. The elastomeric structure of claim 27, further comprising an environmental coating applied to at least a portion of a surface of the fabric.
29. The elastomeric structure of claim 27, further comprising an adhesive for securing the fabric to the elastomeric substrate.
30. The elastomeric structure of claim 28, wherein the environmental coating is comprised of an elastomeric coating of material from the group of fluorosilicones, fluoroelastomers, silicones, thermoplastic elastomers and urethanes.
Description

This application is a divisional application of Ser. No. 08/718,771, filed on Sep. 24, 1996, now U.S. Pat. No. 6,048,581.

FIELD OF THE INVENTION

The present invention relates generally to the field of stretchable fabrics and more particularly to an elastic ground plane and method.

BACKGROUND OF THE INVENTION

Continuous moldline technology using reinforced elastomers presents an opportunity to improve upon many of the performance characteristics of aircraft and missiles. FIG. 1 shows a side view of a rod reinforced elastomer of the prior art. FIG. 2 is a top view of the rod reinforced elastomer of FIG. 1. The rod reinforced elastomer 10 has a pair of rod blocks 12. A plurality of rods 14 anchored to one of the pair of rod blocks 12 slide inside an elastomer panel 16. The rod reinforced elastomer 10 is capable of both elongation and deflection, as shown in FIG. 3. The rod reinforced elastomer has resting length 22 that can be stretched to an elongated length 24 and deflected a distance 26. These products can be used in applications such as control surfaces and in expandable bays to provide cleaner airflow and reduced drag. However, these products so far have been limited to nonmetallic elastomeric compounds that provide little to no protection against electromagnetic interference (EMI). EMI can cause aircraft instruments to malfunction and can result in navigational errors and even the loss of the aircraft.

Conventional EMI shields have been designed as highly conductive metal strips, sprays, and panels that do not possess the ability to flex or elongate repeatedly without material degradation. Recent advances have produced foils that allow a continuous metallic surface with the ability to flex to various shapes. Unfortunately, these foils are limited to applications where elongation is less 10%.

Thus there exists a need for a material that can easily and significantly elongate in all directions, is highly conductive in all states of elongation, can withstand repeated elongations with no degradation in shielding effectiveness or material properties, is thin and light weight, and which is tough enough to withstand severe aerospace environments.

SUMMARY OF THE INVENTION

An elastic ground plane that overcomes these and other problems has an environmental coating attached to a surface of a fabric having a plurality of fibers. A conductive substance is applied to the fabric to coat the fabric.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a prior art rod reinforced elastomer;

FIG. 2 is a top view of the rod reinforced elastomer of FIG. 1;

FIG. 3 is a side view of the rod reinforced elastomer of FIG. 1 in an elongated and deflected state;

FIG. 4 is a side view of an embodiment of an elastic ground plane;

FIG. 5 is a side view of another embodiment of the elastic ground plane; and

FIG. 6 is a side view of another embodiment of the elastic ground plane.

DETAILED DESCRIPTION OF THE DRAWINGS

An embodiment of an elastic ground plane (elastic conductive material) 50 attached to a surface 52 is shown in FIG. 4. The surface 52 could be the rod reinforced elastomer discussed above. Alternatively, the surface could be any surface needing EMI shielding, particularly any surface that tends to stretch or elongate. The elastic ground plane 50 has a fabric 54 containing a plurality of fibers. In one embodiment the fabric is a warp knit fabric (warp knit style weave) made from polyamide NYLON fibers. In addition the fabric may contain a small amount of elastic polyurethane fiber (e.g., approximately 10%). The polyurethane or other elastic fiber assists in the recovery of the material after stretching. Note that the invention is not limited to NYLON or to warp knit weave as other materials and weaves are available. For instance, tubular knit weaves or other weaves that permit reversible elongation without permanent deformation or fabric damage can be used and higher temperature resistant materials such as super polyamide, glass, and quartz fibers can be knit when necessary for increased thermal performance. The fabric 54 is coated with a conductive substance by electrolessly plating the fabric 54 in one embodiment. The electroless plating deposits from five to forty percent (by weight) silver, nickel, copper, tin or other metal or combination of metals 56 on the fabric 54. In another embodiment each of the plurality of fibers forming the fabric (plane) 54 are electrolessly plated and then woven. An environmental coating 58 is then applied over the fabric 54. The environmental coating 58 is an elastomeric coating (elastomer) which can be in the form of fluorosilicones, fluoroelastomers, silicones, thermoplastic elastomers, urethanes or other viable elastic materials. An elastomeric adhesive (adhesive) 60 is applied to a side of the environmental coating 58 to attach the elastic ground plane to the surface 52.

Tests have shown that the elastic ground plane is capable of a minimum of 100% elongation in all directions at the required operating temperature (operating range) (e.g., −65 to 250 Fahrenheit). The elastic ground plane has a resistance of less than 0.8 Ohms per square, even when elongated and after repeated high strain loading conditions, providing an excellent ground plane. The tensile moduli for the material is less than 1,000 pounds per square inch (PSI) over the operating conditions. A low tensile moduli is important when the elastic ground plane is placed on a rod reinforced elastomer. The low tensile moduli allows the rod reinforced elastomer to be elongated and deflected without requiring a large force to drive the rod reinforced elastomer. Placing the elastic ground plane over the rod reinforced elastomer also increases the tear resistance of the elastomer by two and half times.

FIG. 5 shows an alternative embodiment of the elastic ground plane 50. In this embodiment the fabric (plurality of fibers) 54 only has the environmental coating 58 on the top surface of the fabric 54 (as opposed to encasing the fabric as in FIG. 4). The elastomeric adhesive is applied to a second surface of the fabric 54 or to the surface 52, to attach the elastic ground plane to the surface 52. FIG. 6 shows a third embodiment of a process for making and applying the elastic ground plane 50. In this embodiment the conductive fabric 54, 56 is prepared first. Next, the conductive fabric 54, 56 is cleaned with a solvent. Then an elastomeric adhesive 60 is applied to a surface 52 and the fabric 54 is placed on the adhesive 60. Last, the environmental elastomeric coating is applied by a sprayer 62.

Thus there has been described an elastic ground plane that can easily and significantly elongate in all direction, is highly conductive in all states of elongation, can withstand repeated elongations with no degradation in shielding effectiveness or material properties, is thin and light weight and which is tough enough to withstand severe aircraft environments.

While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alterations, modifications, and variations in the appended claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1942867May 17, 1932Jan 9, 1934Goodrich Co B FDeicer for aeroplanes
US2152029May 28, 1936Mar 28, 1939Robert W ConeAirplane wing construction
US2173262May 6, 1938Sep 19, 1939Dana Monegan EdgarDeicer for airships
US2368702Apr 8, 1943Feb 6, 1945Bourne Raymond DStreamlined hinge line for aircraft
US2504684Jan 30, 1946Apr 18, 1950Goodrich Co B FExtensible structure for varying the configuration of an aircraft surface
US2716460Feb 28, 1952Aug 30, 1955Raymond A YoungBlade and control mechanism for helicopters
US2731221Jun 25, 1952Jan 17, 1956North American Aviation IncAircraft door installation
US3586267Dec 17, 1968Jun 22, 1971Sundberg Alf M M IArrangement in and relating to aircraft
US4296900Apr 23, 1979Oct 27, 1981Vought CorporationAirfoil construction
US4427169Jun 8, 1982Jan 24, 1984Boeing Commercial Airplane CompanyVariable camber flap end seal
US4429844Sep 29, 1982Feb 7, 1984The Boeing CompanyVariable camber aircraft wing tip
US4461611May 20, 1982Jul 24, 1984United Technologies CorporationHelicopter rotor with blade trailing edge tabs responsive to control system loading
US4706913Oct 9, 1984Nov 17, 1987The Boeing CompanyVariable camber leading edge assembly for an airfoil
US4892626Jan 21, 1988Jan 9, 1990Boeing CompanyMethod for plating one side of a woven fabric sheet
US4966802May 16, 1989Oct 30, 1990The Boeing CompanyComposites made of fiber reinforced resin elements joined by adhesive
US5094412Oct 13, 1989Mar 10, 1992Bell Helicopter Textron Inc.Flaperon system for tilt rotor wings
US5222699Apr 16, 1990Jun 29, 1993Ltv Aerospace And Defense CompanyVariable control aircraft control surface
US5288039Jul 29, 1992Feb 22, 1994Delaurier James DSpanwise graded twist panel
US5326050Feb 8, 1993Jul 5, 1994The United States Of America As Represented By The Administrator Of National Aeronautics And Space AdministrationAerodynamic surface distension system for high angle of attack forebody vortex control
US5367970Sep 27, 1993Nov 29, 1994The United States Of America As Represented By The Secretary Of The NavyControllable camber fin
US5374011Nov 13, 1991Dec 20, 1994Massachusetts Institute Of TechnologyMultivariable adaptive surface control
US5481184Jun 12, 1992Jan 2, 1996Sarcos GroupMovement actuator/sensor systems
US5487351Jan 13, 1995Jan 30, 1996The United States Of America As Represented By The Secretary Of The NavyControl surface for underwater vehicle
US5639215Feb 26, 1996Jun 17, 1997Advanced Technology Institute Of Commuter-Helicopter, Ltd.Helicopter rotor equipped with flaps
US5662294Nov 20, 1995Sep 2, 1997Lockheed Martin CorporationAdaptive control surface using antagonistic shape memory alloy tendons
US5700337Mar 1, 1996Dec 23, 1997Mcdonnell Douglas CorporationFabrication method for composite structure adapted for controlled structural deformation
US5794893Jun 7, 1995Aug 18, 1998Northrop Grumman CorporationElastomeric transition for aircraft control surface
US5803405Jun 7, 1995Sep 8, 1998Northrop Grumman CorporationExpandable aircraft section
US5806808Sep 5, 1997Sep 15, 1998Mcdonnell Douglas Corp.Airfoil lift management device
US5839700Jun 3, 1996Nov 24, 1998The United States Of America As Represented By The Secretary Of The NavyArticulated fin
US5892877 *Jun 30, 1997Apr 6, 1999Tii Industries, Inc.Optical fiber strain relief system
US5896191May 13, 1997Apr 20, 1999Mcdonnell DouglasReinforced elastomer panel with embedded strain and pressure sensors
US5918834Feb 27, 1997Jul 6, 1999Mcdonnell DouglasRetractable sensor system for an aircraft
US5927651May 15, 1997Jul 27, 1999Mcdonnell DouglasFor an aircraft
US5947417Jul 25, 1997Sep 7, 1999Mcdonnell DouglasFairing for an expandable bay
US5947422Apr 29, 1997Sep 7, 1999Mcdonnell DouglasTail for an aircraft
US5958803 *Mar 13, 1997Sep 28, 1999Mcdonnell DouglasEnvironmental coating for an elastomer panel
US5975463 *Dec 21, 1995Nov 2, 1999Mcdonnell DouglasExpandable aircraft bay and method
US5979828 *Apr 30, 1997Nov 9, 1999Mcdonnell DouglasApparatus for eliminating gaps in an aircraft
US6027074 *Feb 27, 1997Feb 22, 2000Mcdonnell DouglasReinforced elastomer panel
US6048581 *Sep 24, 1996Apr 11, 2000Mcdonnell Douglas CorporationAny surface needing emi shielding, particularly any surface that tends to stretch or elongate, conductive fabric
US6068215 *Dec 21, 1995May 30, 2000Mcdonnall DouglasExpandable aircraft cargo bay and method
US6076766 *Jul 1, 1998Jun 20, 2000Mcdonnell Douglas Corp.Folding wing for an aircraft
US6079667 *Jun 9, 1998Jun 27, 2000Mcdonnell Douglas CorporationAuxiliary inlet for a jet engine
US6089505 *Jul 22, 1997Jul 18, 2000Mcdonnell Douglas CorporationMission adaptive inlet
US6092764 *Jul 21, 1997Jul 25, 2000Mcdonnell Douglas CorporationInterface seal for an aircraft
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6588709Mar 20, 2002Jul 8, 2003The Boeing CompanyApparatus for variation of a wall skin
US7481079Oct 3, 2007Jan 27, 2009Milliken & CompanyCircular knit fabric and method
US7896294 *Nov 23, 2005Mar 1, 2011Airbus Deutschland GmbhCover skin for a variable-shape aerodynamic area
Classifications
U.S. Classification442/71, 442/180, 442/317, 442/304, 442/117
International ClassificationB64D45/02, B32B5/02
Cooperative ClassificationB64D45/02, B32B5/02
European ClassificationB32B5/02, B64D45/02
Legal Events
DateCodeEventDescription
Mar 14, 2013FPAYFee payment
Year of fee payment: 12
Jul 8, 2009FPAYFee payment
Year of fee payment: 8
Jul 8, 2005FPAYFee payment
Year of fee payment: 4